Study registration: *
Publication Chemaitelly H, N Eng J Med, 2021
Dates: 2021-01-01 to 2021-09-05
Funding: Mixed (Biomedical Research Program and the Biostatistics, Epidemiology, and Biomathematics Research Core at Weill Cornell Medicine–Qatar; the Ministry of Public Health; and Hamad Medical Corporation. The Qatar Genome Program provided the reagents for the viral genome sequencing.)
Conflict of interest: no COI (Hiam Chemaitelly, Laith Abu-Raddad I do not have any interests to disclose at this time.)

Methods

Study design:Test-negative
Description of participants: Adults and children with PCR-confirmed/negative SARS-CoV-2 in Qatar.
Inclusion criteria:
  • Only the first PCR-positive test during the study, January 1, 2021 to September 5, 2021, was included for each case, and only the first PCR-negative test during the study was included for each control.

Exclusion criteria:
  • All PCR tests done for pre-travel or at the port of entry were excluded from analysis, except in a sensitivity analysis
  • all PCR-negative tests for persons included as cases were excluded from analysis
  • all persons who received mixed vaccines, or who received a vaccine other than BNT162b2 were excluded.

Follow-up duration (months): 8.2
Vaccines:
  • 1 or 2 doses of BNT162b2
Variant description :
Variant name: Delta
Evidence: Direct evidence (effectiveness determined by sequencing cases)
Documents
available

Protocol

NR

Statistical plan

NR

Data-sharing stated: NR
Data accessibility: NR
General comment Concerns over uncontrolled confounding, particularly by socioeconomic status and comorbidities.